Yosuga No Sora Steam Skin

O anime:
Haruka Kasugano and his twin sister Sora have lost both their parents in
an accident, and with them all their support. They decide to move out
of the city to the rural town where they once spent summers with their
late grandfather. At first everything seems familiar and peaceful, but
changes come as Haruka starts to remember things from his youth
Źródło: http://myanimelist.net/